This survey is designed to be used in face to face interviews. The key feature described is answer masking.
Masking hides or shows answer choices depending on answers previously given, allowing the researcher to gather more detail and avoid wasting the respondents time.
Further interactivity is provided by the use of derived variables, which perform in-survey calculations based on answers given during the interview. In this example, the result of that calculation is presented in the questionnaire.
For an explanation of features included in this survey, hover over the symbol wherever it appears